ECC Unit 3 Mathematical/Simulation Unit - Investigators: Lawrence Sirovich, Fernand Hayot, Upinder Bhalla, Charles Peskin and David McQueen This unit will be located in New York and distributed between Mount Sinai and NYU Courant. Only software development will be done at NCBS in Bangalore India under the leadership of Upi Bhalla. Progress in the study of physioloigcal regulatory systems has advanced to a stage where closely associated theoretical research is required. Mathematics coupled with computational simulations provides the ideal framework for this endeavor. Mathematics allows for the development of theoretical models of biological systems that can generate predictions and suggest experimental tests to either confirm or refute the models. All four of the research projects in the SBC will use computational modeling as a means of developing hypotheses and understanding experimental data. Mathematical techniques can also be used to organize and interpret experimental data, particularly in this era in which high-throughput techniques produce extremely large data sets. These observations provide compelling arguments for a mathematics/simulation unit with the ECC. The goals of this Unit are to: 1. Develop mathematical tools for the analysis and simplification of large-scale complex dynamical systems. Provide these tools to the investigators of the SBC for use in their research projects, and disseminate these results to the research community at large. 2. Build computer algorithms that use these novel tools and can be distributed widely. Serve as a general source of mathematical/simulation expertise within the SBC and the larger scientific community 3. Establish and promote collaborations with scientists outside the Center on projects that can benefit from mathematical/computational methods. Facilitate interactions between the researchers involved in these projects and the students, postdoctoral fellows, and investigators already associated with the SBC.